Eligibility screening in evidence synthesis of environmental management topics

The eligibility screening step of a systematic review or systematic map (sometimes referred to as ‘study selection’, ‘evidence selection’ or ‘inclusion screening’) determines the scope of the evidence that may answer the review or map question. Eligibility screening involves the development, testing and application of eligibility criteria (inclusion and exclusion criteria) by an evidence synthesis review team, based on methods pre-specified in the review or map protocol. Some parts of the process require judgement, meaning that consistent and transparent reporting of the eligibility criteria and the process for applying them are essential in order to reduce the risk of introducing errors or bias. The existing Collaboration for Environmental Evidence (CEE) Guidelines for Systematic Reviews in Environmental Management (version 4.2, March 2013) give relatively limited guidance on how to conduct eligibility screening. In this paper we provide more in-depth information on good practice methods for this step of evidence synthesis, based on a critical consideration of existing guidance and current practice. Our aim is to provide recommendations to support those conducting CEE systematic reviews or systematic maps for environmental management questions; however, the methods we describe are generic and should be broadly applicable across a wide range of environmental research topics.